Andrew,

For my tests the "clear selected ketframes" problem is solved.
There is the problem that subsequent edits are changed according to
the range value, even if they are out of the range. Also it seems that
the created interval remains the same length and does not adjust to
the resizing of the edits.
See the following movie (it is for download because it is too big to
streamable):

https://www.dropbox.com/s/z3na1r3vmwcnn6n/test.webm?dl=0

Thanks for testing and the demo.  A fix has been checked into GIT.  It was a blunder -- missing "that"!
void Auto::copy_from(Auto *that)
 {
-       this->orig_id = orig_id;
+       this->orig_id = that->orig_id;
        this->position = that->position;